Self-Help Plus (SH+) for Stress Reduction in Social Service Workers: A Pilot RCT

Social service workers are chronically exposed to traumatic content and occupational stress, placing them at elevated risk for psychological distress and secondary traumatic stress. A universal-prevention approach is adopted: no individual stress threshold is required for inclusion, as the occupational context itself serves as a high-risk filter.

Randomization is performed at the institution (cluster) level rather than the individual level to prevent contamination, accommodate the group format of the intervention, and reflect logistical realities of the institutions. Two clusters are allocated to the intervention arm and two to the control arm (1:1), stratified by service type. The allocation list is generated by a researcher independent of the field team, and assignment is revealed only after baseline (T0) assessment is complete. The trial is single-blind: participants and facilitators cannot be blinded, but outcome assessment is self-report via online forms (structural assessor masking) and the data analyst is blinded to group allocation (groups coded A/B until analysis is complete).

The SH+ intervention is a low-intensity, guided self-help program based on Acceptance and Commitment Therapy, delivered by trained non-specialist facilitators in a group format across five weekly sessions of approximately two hours each. It uses a pre-recorded audio course complemented by the illustrated self-help book "Doing What Matters in Times of Stress"; participants receive the book and weekly audio exercises for between-session practice. The ECAU control comprises continued access to existing institutional support and routine services plus a comprehensive psychoeducational information pack (stress-coping strategies, recognition of stress symptoms, and pathways to mental health and psychosocial support services in Istanbul). After the 3-month follow-up (T2), control-arm participants are offered the opportunity to attend SH+ sessions.

Assessments are collected at baseline (T0, pre-randomization), post-intervention (T1), and 3-month follow-up (T2) via self-report online forms. Feasibility progression thresholds are pre-specified: recruitment rate ≥70%, session attendance ≥70% (attending at least 3 of 5 sessions), and follow-up completion ≥75%. Preliminary effectiveness is analyzed using design-effect-adjusted methods or linear mixed models accounting for clustering; effect sizes (Cohen's d) with 95% confidence intervals are reported. The intraclass correlation coefficient (ICC) for the primary clinical outcome (PSS-10) is estimated to inform sample-size planning for a future full-scale cluster RCT.

• Self-Help Plus (SH+) (Behavioral): WHO Self-Help Plus: a low-intensity, ACT-based guided self-help program delivered by trained non-specialist facilitators in a group format over five weekly sessions (approximately 2 hours each), using a pre-recorded audio course and the illustrated self-help book "Doing What Matters in Times of Stress."
• Enhanced Care as Usual (ECAU) (Behavioral): Continued access to existing institutional support and routine services plus a comprehensive psychoeducational information pack on stress-coping strategies, recognition of stress symptoms, and referral pathways to mental health and psychosocial support services

Primary outcomes

• Recruitment rate (feasibility) [Through completion of enrollment and baseline assessment (T0), approximately Month 1]: Proportion of eligible staff who provide consent and enroll, calculated as the number enrolled divided by the number eligible, expressed as a percentage. A priori progression threshold is set at 70% or higher.
• Session attendance rate (feasibility) [Across the 5-week intervention period (Weeks 1 to 5)]: Proportion of intervention-arm participants attending at least 3 of the 5 SH+ sessions, expressed as a percentage. A priori threshold is 70% or higher.
• Follow-up completion / retention rate (feasibility) [From baseline (T0) to 3-month follow-up (T2)]: Proportion of enrolled participants completing the 3-month follow-up (T2) assessment, expressed as a percentage. A priori threshold is 75% or higher.
• Acceptability and participant satisfaction (feasibility) [At post-intervention (T1), approximately Week 5-6]: Participant-reported acceptability and satisfaction with the intervention, assessed using the purpose-built SH+ Programme Evaluation Form.

Secondary outcomes

• Change in perceived stress (PSS-10) [Baseline (T0), post-intervention (T1), and 3-month follow-up (T2)]: Perceived Stress Scale (PSS-10), a 10-item self-report measure with a total score ranging from 0 to 40; higher scores indicate greater perceived stress. Between-group comparison of change from baseline.
• Change in depressive symptoms (PHQ-9) [Baseline (T0), post-intervention (T1), and 3-month follow-up (T2)]: Patient Health Questionnaire-9 (PHQ-9), a 9-item self-report measure with a total score ranging from 0 to 27; higher scores indicate more severe depressive symptoms.
• Change in anxiety symptoms (GAD-7) [Baseline (T0), post-intervention (T1), and 3-month follow-up (T2)]: Generalized Anxiety Disorder-7 (GAD-7), a 7-item self-report measure with a total score ranging from 0 to 21; higher scores indicate more severe anxiety symptoms.
• Change in professional quality of life (ProQOL-IV) [Baseline (T0), post-intervention (T1), and 3-month follow-up (T2)]: Professional Quality of Life Scale (ProQOL-IV), a self-report measure assessing compassion satisfaction, burnout, and secondary traumatic stress (compassion fatigue) subscales.
• Change in well-being (WHO-5) [Baseline (T0), post-intervention (T1), and 3-month follow-up (T2)]: WHO-5 Well-Being Index, a 5-item self-report measure; the raw score is transformed to a 0 to 100 scale, with higher scores indicating better well-being.

Other outcomes

• Intraclass correlation coefficient (ICC) for PSS-10 [Through 3-month follow-up (T2)]: Intraclass correlation coefficient for the primary clinical outcome (PSS-10), estimated to inform the design effect and sample-size calculations for a future full-scale cluster randomized controlled trial.
• Contamination in the control arm [Post-intervention (T1) and 3-month follow-up (T2)]: Self-reported exposure of control-arm participants to SH+ materials, sessions, or content during the study period, reported descriptively to assess the feasibility of cluster randomization.

Sex: All, ages: 18 Years to any, accepts healthy volunteers

Inclusion Criteria:

* Currently employed (permanent, contracted, or temporary staff) at an institution under the Istanbul Provincial Directorate of Family and Social Services
* Able to read and write in Turkish
* Willing to participate voluntarily
* Provides written informed consent

Exclusion Criteria:

* Imminent suicide risk, screened at baseline (T0) via PHQ-9 item 9; participants scoring 2 or higher are not enrolled and are immediately referred to a mental health professional
* Active psychosis, severe substance use disorder, or severe intellectual disability
* An acute medical condition that would preclude participation
* Planned extended leave (e.g., maternity or unpaid leave) during the study period